No. Check where the blooms are. Most are at the end of a stalk. If you "reduce" the foliage you are cutting off the blooms. No bloom no display.

If they were tree peonies then that is different but needs more than one years work.

If you fertilize always use a fertilizer with the nitrogen number smaller than the other two. Al

Thanks for the help, I really appreciate it but I wondered if by cutting back the foliage early on, as I do my mums for instance, then I would have a stockier plant when it blooms, perhaps that does not apply to peonies, also Al, thanks for the suggestion but I never fertilize my peonies, apparently they prefer not to have fertilizer at all,although occasionally I do give them a handfull of bonemeal. R.

These form their bloom buds as part of that main stem and they can't be cut back like mums. Ie., it seems that many of the plants that come from bulbs, tubers, corms, or rhizomes like peonies, irises, lilies, tulips, daffodils, etc., have that similar habit. A Peony's side-buds can be removed to increase the size of the main bud, but as far as I know, the herbaceous ones don't branch when pruned.

You might consider supporting them with those 3ft tall inexpensive metal tomato cages. As the foliage fills out, it should hide the cage.

Our peonies are the normal peonies I believe but they are still to tall for the peony metal frames for this purpose. WE have found this to produce the best results. First we use the metal frame. Then with 2 people doing this we have one person stand in one place and hold the end of a piece of fishing line while the other person circles the entire plant with line pulling in the stems but not to terribly tight or it will look funny. The person circles twice and fixes the tightness they think looks best and then ties the line in a knot. You should be able to pull out a few leaves too make it look fine. Now when it flowers the flowers stand upright instead of falling to the ground. When they are done flowering you can cut off the flowers but becareful cutting the stems that had the flower on it. Do not cut the fishing line. With the line still intact the plant stays upright all season long and looks good.
Hope this helps. Good luck!

I also have the problem of too-tall peonies. While my system of stakes and green twine supported the stems with only foliage this year, the stems with blossoms STILL bent from the weight, in some cases right over the twine!

The tomato cages are one idea I hadn't thought of; since they are as tall as the flowering stems it sounds sensible to me! A suggestion I read (too late to implement this year) in "The Well Maintained Perennial Garden" is to prune off the central bud (when all are still small) which tends to produce the gigantic, heaviest flowers. (Has anyone tried this?) Another suggestion, from "365 Days of Gardening," was to water the plants with seaweed extract "to make strong stems." I will try that too, but tend to think fix #1 more plausible, coming from a gardening expert who has (presumably) tried this successfully herself.

Rick Rogers of Brothers Tree Peonies suggests using kelp and fishmeal in place of the other foods. I was able to speak with him this spring and asked what he would recommend other than bonemeal when he suggested the use. First though before you start adding a lot of extra food for your plants get a soil test. It always amazes me when I hear of people applying lime to soil when the underlying rocks are limestone. I guess that most people don't know that the majority of lime is just ground up limestone.